It looks like those are pages from some aviation history book, not actual testing.
Nowever here it is. My apologies for messing up terminology and grammar. Russian language is frigging complex.
Starts with second half of sentence-"fight,
capable to "wrestle" with enemy fighters.
That's why when P 51 was received in USSR from England,
opinions of Soviet Aviation Specialist were different
than English. Testing of P-51 by VVS ended in July of 1942.
Main results listed in graff #3 and pic#2.
With given respect to positive qualifications of that aircraft,
Soviet military specialists noted that in most important fighter
aspects like speed, climb rate and maneuverability P-51 is inferior
to Soviet and newer German fighters. Indeed Soviet Yak-7B with
engine M-105pf has climb rate of 5 kilometers in 5.8-6 min,
German Me-109F 4.8-5.4 min, but P-51 in 9 min. and that is
with using WEP for 5 min. Attack climb with turn? of Mustang
(550 meters) was almost twice less than Yak-1,Yak-7b,La5 and
Me-109F and G. Of course given these characteristics Mustang is
unable to fight with German fighters. Lets not forget that
USSR received the very first model of that machine.
At this time USA is already developing special variant for
ground attack, A-36a. After that follows P-51A(1943).
Those aircraft were equipped with more powerful variants of
Allison engine. Specs of P-51a "Mustang 2" improved but not to the level
of competing with FW190 and Me109. Mostly Mustang with Allison engines
were used for reconnaissance and as ground attackers."
Other page. Doesn't seem like its continuation of first one.
"We should mention that Designers achieved their goal,
aerodynamic co efficiency with minor attack angle is very little.
Its lower than mass produced aircraft of those years, and only
later that number was lower in P-63 "Kingkobra".
English and American fighters (except P39 and P63) had one thing in common,
un synchronised weapons located in wings. P51 in the beginning stages of development
was a rare exception: two high caliber synchronised machine guns
for shooting trough propeller and other 6 were wing mounted.
English specialists familiarised with Mustang and admitted that
so far Mustang was the best of all American fighters.
But due to not powerful enough engine for high altitudes anything out of extraordinary
in the air was not expected. Some advantages such as high speed,
medium altitude maneuverability, Long range and good armament
(3.42 kilograms per sec), gave Mustang qualities of reconnaissance and ground attacker.
And it was used as such.
Should be mentioned that English and Americans wildly used fighters as ground attackers.
Part of it is due to unavailability of specialized armored "Shturmoviks" that require
different tactics in air warfare. Sometimes fighters were re equipped for ground attack and
Bomber hunting. They were well known English "Typhoon", "Tempest", American P-39,
P-40 and others. In USSR that character of action was not the most important.
It wasn't the result of some tactical doctrine. It was necessity of Life.
In 1941-1942 soviet VVS was in need of, firstly air fight".......Sentence ends